The biggest thing I was unsure of was how they'd be loaded. I was really only thinking of impact loads from rapid wheel motion like when hitting a pothole or going over curbing. It's not hard to flip the pockets, neither would creating drain holes. If I do that I'd probably taper the pocket into the drain hole.

I still need to add a small post for a threaded hole as I intend to keep the ebrake cable mounting hole.

 

Dude, you're not scratching my impulse purchase itch for the street parts!
Have a track weekend 2/24-25 and I'm dropping the front subframe this weekend anyway...

 

Once you add a big curve as needed for tire clearance then you'll see the direction theyre loaded better. The load to consider would probably be a wheel hop scenario, but my trick on understanding max loads is to find something in the system that doesnt really break, find out the force needed to break it, exceed that in design so its still the failure point.

Typically its been the ball joints and tie rods that have been my go-to for exceeding their failure loads.

Doh, I was trying to remember who it was that needed these super soon and thought I found the guy. Apparently I combined two people and didnt make the extra set.

I do have a set for Mychailo of the 1.25" getting anodized right now but he also wants some other plates to get anodized at the same time. Might be able to convince him I'll just make him a new set of bodies to go with the other plates and I have all the rest of the parts getting done for an extra set anyways.

If youre really interested I can try and make that happen, uprights should be done at anodizing towards end of next week.

 

Dallas do you think there would be any benefit in offsetting the arm upwards at the front bushing to get it closer to being level on lowered cars? I've never really thought about how a trailing arm affects suspension other than keeping the wheel where it is.

 

Certainly there are geometry things to fix. That trailing arm angle effects squat on acceleration, with the lower car making less squat to a point where you can actually get lift. I need to start modeling the rear geometry to see where we can improve things. Certainly resetting camber curves, correcting the trailing arm angle, and fixing bump steer is where Im starting.

 

Messed around with it a bit more. I did give it some more curvature and kind of see what you mean about the load.

In regards to the offset, would you say a level trailing arm is desirable or is that moreso dependent on the rest of the suspension setup?

 

if you are doing a custom arm, use the opportunity to upgrade to spherical joints on both ends..

 

Cant really do spherical on both, its just a two point member and not straight. So it will sag without one end to locate it in rotation. Might be able to do that with a spherical and filling with urethane or something though?

 

My plan was to retain the ball joint on the one end and make it accept a poly bushing on the forward end. If there's a decent benefit to putting a spherical in the front then I could do that pretty easily. I don't really see how a spherical would be an upgrade because it wouldn't resist any torsional load put through the arm.

 

This topic is giving me some ideas, but its going to make the billet rear less of a piece meal upgrade. path. Though I suspect the guys that go that far, probably don't care.

 

Haha I was hoping you'd get crazy with it. I'm thinking of making the one I'm working on a universal drop in piece so it works on either side of the car and drops into the car with the ability to keep the rest of the suspension arms factory/aftermarket replacements so the more average guys have an intermediate option.

 

yes you are right, I wasnt clear.. On mine I pressed in a spherical on the chassis side, but kept the two side rubber donuts.. those keep it aligned so that it doesnt sag..

 

Offsetting where the arm attaches to the pivot point does nothing to change geometry. You have to change the location of the pivot. Similar to the front end, you would use an extended ball joint or custom knuckle.

 

Thanks, I was having a tough time envisioning how/if it would change things as the suspension traveled.


Here's where I left off last night. Rounded out the pockets, added in drainage holes, and added the small post for the ebrake cable. The ebrake post is on both sides of the arm, so it can be used on either side of the car.

 

Dallas I'll take a set of those rear top hats for the DFVs as well. Let us know when they are done.